The present invention is directed to an improved process of preparing metallic detergent-dispersant additives of high alkalinity, in particular, for lubricating oils, and to the additives and lubricating oils containing the additives.
French Pat. No. 1,356,763 discloses that basic sulfurized alkylphenates can be prepared by sulfurizing an alkylphenol in the presence of a metallic sulfonate, a C.sub.8 -C.sub.18 monoalcohol, an alkaline-earth metal base and ethylene glycol; followed by carbonation with carbon dioxide. Such a process has the drawback of requiring relatively large amounts of ethylene glycol and, furthermore, the presence of a monoalcohol.
By the present invention, an improved process has been provided which does not have the drawbacks of the prior art for obtaining metallic detergent-dispersant additives of a TBN (Total Basic Number, ASTM Standard D 2896) greater than 200, and to do so in a simple and rapid manner in the presence of a monoalcohol being required.
It is, therefore, an object of the present invention to provide novel detergent-dispersant compositions useful as additives for lubricating oils having a base of alkylbenzene sulfonates and alkylphenates.
It is also an object of the present invention to provide a novel process for the preparation of detergent-dispersants for use in lubricating oils.
It is also an object of the present invention to provide lubricating oils containing the novel additives of the invention.
Other objects of the present invention will be apparent to those skilled in the art from the present description.